In recent years, mobile phones and portable information terminals such as smartphones have a tethering function as a technique for connecting a portable information terminal to abase station so as to operate as a wireless router, connecting other personal devices with the portable information terminal by wireless LAN, and thereby connecting these devices to a network via the portable information terminal.
For example, in Patent Document 1, an advanced tethering system has been proposed to be provided, in which a portable information terminal can access the Internet via a host terminal operating as a wireless router and use other services (applications).